Question

{Will give medal} Quick question: How do I finish this problem?

A rectangular field will be fenced on all four sides. Fencing for the north and south sides costs $10 per foot and fencing for the other two sides costs $9 per foot. What is the maximum area that can be enclosed for $6000?

20L+18W=6000

18W = 6000 - 20L

W = 1000/3 - 10L/9

A = L*W

A = L (1000/3 - 10L/9)

A = 1000L/3 - 10L^2/9

Answer 1

what are my options?

Answer 2

This is not a multiple choice question, the answer box is _______ ft sq

Answer 3

ok give me a sec.

Answer 4

give me help what do you think is the answer?

Answer 5

I don't know, I'm stuck...

Answer 6

ok lets work together. What do we know?

Answer 7

https://answers.yahoo.com/question/index?qid=20100706114608AAAUqMz

Answer 8

Same problem, different numbers. I'm good until:


dA/dL = 250 - L = 0

Answer 9

got to go sorry.

Answer 10

Look at a different way. You have an equation of a parabola that opens downward. So the maximum area is going to be at the vertex.

To find the value of L at the vertex, use the formula -b/2a. Where b is 1000/3 and a is -10/9